GENERAL
=======

This is a modified version of GiST library plus
an implementation of an new R-tree index that uses
k-means algorithm for node splitting.

The modification of the core libgist library was
necessary in order to support splitting in more
than two nodes.

The new indexing method has been integrated
into the GiST package. This means that you can
manipulate the new index through both gist command
line and amdb environments.


INSTALLATION ISSUES
===================

There shouldn't be any special issue concerning the 
installation, compilation and execution of the modified 
package. Just follow the original GiST instructions 
in GiST User manual, Gistcmdline reference, Guide to 
writing libgist extensions supplied with the original 
package. Note that the HMETIS package is needed for 
the amdb analysis functions.


MODIFICATION DETAILS
====================

The name of the new indexing method as seen
in the command line and amdb environments is
rclustms.

The files relevant to the index implementation are
libgist\include\gist_rclustms.h
libgist\src\librtree\gist_rclustms.cc
libgist\src\librtree\kmeans.h
libgist\src\librtree\kmeans.cc
Changes were made to the rectangle predicate class. We 
added distance fuctions for rectngles. So, these were
modified:
libgist\include\gist_rtpred_rect.h
libgist\src\librtree\gist_rtpred_rect.cc

The files modified in order to "make visible"
the rclustms index to gist command line and amdb 
environments are:
libgist\include\gist_ext.h
libgist\src\cmdline\cmdline.cc
libgist\src\librtree\amdb_rtree.cc

In order to support multisplitting we declared the
insert() method of the gist class virtual. We 
subclassed class gist and made gist_ms where we
provided new versions of _apply_update(), _split(),
_split_node(), and _update_parent() methods. The 
files relevant to the core library modifications are:
libgist\include\gist.h
libgist\include\gist_ms.h
libgist\include\gist_defs.h
libgist\src\libgist\gist.cc
libgist\src\libgist\gist_ms.cc

_